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"Espejo mágico": caso práctico de una aplicación basada en realidad aumentada = "Mirror magic": an application based on augmented reality to visualize virtual clothes

  • Cogollor Fernández, Miguel Rubén
Este proyecto pretende acercar la potencia de la realidad aumentada mediante la ejecución de un caso práctico, el cuál engloba sus diferentes casos de uso en la actualidad, así como crear un sistema de tracking y su configuración mediante la herramienta de ARToolkit (https://github.com/artoolkit) La realidad aumentada (AR) a diferencia de la realidad virtual (VR) agrega elementos virtuales a una realidad existente y esto se realiza mediante un sistema de tracking de objetos reales los cuales son sustituidos por sus homólogos virtuales. Este sistema es posible mediante la creación de patrones que en el caso de este proyecto primero fueron entrenados bajo la cámara de un ordenador para que pudieran ser sustituidos por objetos 3D programados en C, con el uso de OpenGL. El objetivo general de este proyecto es desarrollar una aplicación para mostrar cómo podemos usar la Realidad Aumentada para diseñar nuestra propia ropa y visualizar cómo nos quedaría al vestirla. En este caso, utilizamos solo una camiseta para mostrar diferentes diseños, pero también podemos usar un pantalón, un sombrero o incluso un traje o un vestido. Solo tenemos que imprimir en nuestra ropa los patrones o marcadores que nuestra cámara convertirá en diseños virtuales.---ABSTRACT--- Augmented Reality applications augment the real environment with virtual embedded information that appears to be consistently registered in 3D with real spatial locations; Augmented Reality has an advantage over Virtual Reality because the real environment contains a richness of information and user-interaction techniques that cannot yet be reached by synthetic environments. Several Augmented Reality systems have been developed but most of them are based on bulky, expensive and intrusive hardware; a cheaper, less intrusive and more portable hardware solution is given by modern handheld devices that are gaining in performance every year (thanks mostly to dedicated CPUs and embedded peripherals) and are now effectively an off-the-shelf compact solution for Augmented Reality applications. The purpose of the present thesis project is to design and implement an application based on Augmented Reality to visualize a three-dimensional virtual object or a text in a t-shirt. This application is based on ARToolKit which is a software library for building Augmented Reality (AR) applications. These are applications that involve the overlay of virtual imagery on the real world. A three-dimensional virtual character appears standing on a real card. It can be seen by the user in the head set display they are wearing. When the user moves the card, the virtual character or text moves with it and appears attached to the real object. The overall goal of this project is to develop a case-study application to show how we can use the Augmented Reality to design our own clothes and visualize how its look likes. In this case, we use just a t-shirt to show different designs but we can use also a trouser, a hat or even a suit or a dress. Just we need to print in our clothes the patterns or markers that our camera will become into virtual designs.
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Estudio experimental de la fisuración de la fábrica de ladrillo bajo solicitaciones de tracción y cortante = Experimental scale model study of cracking in brick masonry under tensile and shear stress

  • Reyes Pozo, Encarnación
  • Casati Calzada, María Jesús
  • Gálvez Ruiz, Jaime
Este artículo presenta los resultados de la investigación realizada sobre el comportamiento en rotura de la fábrica de ladrillo bajo solicitaciones de tracción y cortante. La investigación está encaminada a proporcionar modelos de ensayo y resultados experimentales que permitan conocer mejor los procesos de agrietamiento de la fábrica de ladrillo bajo tensiones normales de tracción y tangenciales. Se presentan los resultados de una campaña experimental desarrollada con dos tipos de probeta: 1) la probeta compacta con doble entalla solicitada a compresión asimétrica, y 2) la probeta de flexión con entalla solicitada bajo carga asimétrica aplicada en tres puntos. Se han ensayado probetas de dos tamaños semejantes (razón de semejanza 2) y varias orientaciones de los tendeles, con el fin de ver cómo afecta la orientación de los tendeles en la propagación de las grietas. Los ensayos se han realizado con probetas a escala 1/4 de un muro de fábrica de ladrillo de una hoja a soga de medio pie de espesor. This article discusses the results of research conducted on the failure behaviour of brick masonry under tensile and shear stress. The study was designed to develop test models and generate experimental results able to provide greater insight into tensile and shear stresses cracking in brick masonry. The results of a campaign conducted with two types of specimens are discussed: 1) double-edge notched specimens under non-symmetrical compression stress, and 2) three point bending specimens under nonsymmetrical loading. Tests were run on specimens of similar size (similarity rate 2) and different bed joint orientation to determine how bed joint orientation affects crack propagation. The tests were conducted on scale models (1/4) of a single wythe, stretcher bond brickwork masonry wall one half foot thick.
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Universal Scaling, Entanglements, and Knots of Model Chain Molecules

  • Foteinopoulou, Katerina
  • Karayiannis, Nikos Ch.
  • Laso Carbajo, Manuel
  • Kröger, Martin
  • Mansfield, Marc L.
By identifying the maximally random jammed state of freely jointed chains of tangent hard spheres we are able to determine the distinct scaling regimes characterizing the dependence of chain dimensions and topology on volume fraction. Calculated distributions of (i) the contour length of the primitive paths and (ii) the number of entanglements per chain agree remarkably well with recent theoretical predictions in all scaling regimes. Furthermore, our simulations reveal a hitherto unsuspected connection between purely intramolecular (knots) and intermolecular (entanglements) topological constraints.
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Bowing of the band gap pressure coefficients in InGaN alloys

  • Franssen, G.
  • Gorczyca, l.
  • Suski, T.
  • Kamińska, A.
  • Pereiro Viterbo, Juan
  • Muñoz Merino, Elias
  • Lliopoulus, E.
  • Georgakilas, A.
  • Che, S.B.
  • Ishitani, Y.
  • Yoshikawa, A.
  • Christensen, N.E.
  • Svane, A.
The hydrostatic pressure dependence of photoluminescence, dEPL/dp, of InxGa1−xN epilayers has been measured in the full composition range 0_x_1. Furthermore, ab initio calculations of the band gap pressure coefficient dEG/dp were performed. Both the experimental dEPL/dp values and calculated dEG/dp results show pronounced bowing and we find that the pressure coefficients have a nearly constant value of about 25 meV/GPa for epilayers with x_0.4 and a relatively steep dependence for x_0.4. On the basis of the agreement of the observed PL pressure coefficient with our calculations, we confirm that band-to-band recombination processes are responsible for PL emission and that no localized states are involved. Moreover, the good agreement between the experimentally determined dEPL/dp and the theoretical curve of dEG/dp indicates that the hydrostatic pressure dependence of PL measurements can be used to quantify changes of the band gap of the InGaN ternary alloy under pressure, demonstrating that the disorder-related Stokes shift in InGaN does not induce a significant difference between dEPL/dp and dEG/dp. This information is highly relevant for the correct analysis of pressure measurements
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Cohesive crack model for mixed mode fracture of brick

  • Reyes Pozo, Encarnación
  • Casati Calzada, María Jesús
  • Gálvez Ruiz, Jaime
This paper presents a numerical procedure for mixed mode fracture of brickworkmasonry. Themodel is an extension of the cohesive model prepared by the authors for concrete, and takes into account the anisotropy of the material. After the crack path is obtained, an interface finite element (using the cohesive fracture model) is incorporated into the trajectory. Such a model is then implemented into a commercial code by means of a user subroutine, consequently being contrasted with experimental results. Fracture properties of masonry are independently measured for two directions on the composed masonry, and then input in the numerical model. This numerical procedure accurately predicts the experimental mixedmode fracture records for different orientations of the brick layers and two homothetic sizes on masonry panels.
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A quantitative analysis of complementation of deleterious mutants in plant virus populations

  • Fraile Pérez, Aurora
  • Sacristán Benayas, Soledad
  • Garcia-Arenal Rodriguez, Fernando
Complementation can be defined as the process by which the function affected by a mutation is provided in trans by fully competent genotypes. Complementation can, thus, counter the effects of selection of deleterious mutants. Complementation of mutants defective for replication, movement and transmission has been often described in experiments with viruses and, occasionally, has been reported to occur in their natural populations. However, the role of complementation in virus evolution has been overlooked. Here is provided a quantitative estimate of the efficiency of complementation, defined as the probability that a non-functional mutant accomplishes a function relative to a functional one. For this, the frequency of mutants of Tobacco mosaic virus (TMV) defective for cell to cell movement was estimated in wild type tobacco plants and in transgenic plants expressing the TMV movement protein (MP) from a transgene. Mutants lethal for cell-to-cell movement were complemented by wild-type TMV in the first case, and by the transgene-expressed MP in the second case. Assuming that complementation is fully efficient in the transgenic plants, a value for the efficiency of complementation of 0.34 was obtained. Thus, complementation can efficiently counter selection on lethal mutants, and may have an important role on virus evolution. Complementation may be relevant for management of viral diseases if the complemented deleterious mutation is linked to other functions affecting the pathogenicity or epidemiology of the virus. - La complementación puede definirse como el proceso por el cual una función afectada por una mutación es provista en trans por genotipos competentes para dicha función. La complementación de mutantes defectivos para replicación, movimiento o transmisión se ha descrito con frecuencia en poblaciones experimentales de virus y, ocasionalmente, en poblaciones de campo. Sin embargo, el papel de la complementación en la evolución de los virus no se ha considerado. En este trabajo presentamos una estima de la eficacia de la complementación, definida como la probabilidad de que un mutante no funcional realice la función respecto a un genotipo funcional. Para ello se estimó la frecuencia de mutantes del virus del mosaico del tabaco (TMV) defectivos para el movimiento de célula a célula en plantas silvestres de tabaco y en plantas transgénicas que expresan constitutivamente la proteína del movimiento (MP) de TMV. En el primer caso, los mutantes letales para movimiento serán complementados por genotipos silvestres de TMV, y en el segundo, por la MP transgénica. Suponiendo que la complementación en las plantas transgénicas es totalmente eficaz, se obtuvo un valor de la eficacia de complementación de 0,34. Esto muestra que la complementación puede contrarrestar eficazmente el efecto de la selección sobre mutantes deletéreos y tener un papel importante en la evolución de virus, con importantes implicaciones prácticas si la mutación deletérea complementada está ligada a otras funciones que afecten a la patogenicidad o epidemiología del virus.
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Resonant Raman study of local vibrational modes in AlGaAsN layers

  • Gallardo Velasco, Eva María
  • Lazic, Snezana
  • Calleja Pardo, José Manuel
  • Miguel-Sanchez, J.
  • Montes Bajo, Miguel
  • Hierro Cano, Adrián
  • Gargallo Caballero, Raquel
  • Fernández González, Alvaro de Guzmán
  • Muñoz Merino, Elias
  • Teweldeberhan, A.M.
  • Fahy, S.
We report on resonant inelastic light scattering in dilute AlGaAsN films. Intense narrow peaks associated to N-related local vibration modes (LVM) have been observed around 325, 385, 400, 450, 500 and 540 cm−1. Their frequencies are compared to density functional theory supercell calculations of AlnGa4−nN complexes (n=1−4). We find clear indications of the formation of Al4N complexes. The values of the extended phonon frequencies reveal changes in the N distribution depending on the growth conditions. The LVM spectra are resonant in the energy range from 1.75 to 1.79 eV, which corresponds to an N-related electronic transition. Our results confirm the preferential bonding of N to Al in AlGaAsN.
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Local vibration modes and nitrogen incorporation in AlGaAs: N layers

  • Gallardo Velasco, Eva María
  • Lazic, Snezana
  • Calleja Pardo, José Manuel
  • Miguel-Sanchez, J.
  • Montes Bajo, Miguel
  • Hierro Cano, Adrián
  • Gargallo Caballero, Raquel
  • Fernández González, Alvaro de Guzmán
  • Muñoz Merino, Elias
  • Teweldeberhan, A.M.
  • Fahy, S.
Raman scattering measurements in dilute AlGaAs:N films grown by plasma-assisted molecular beam epitaxy on (100) GaAs substrates reveal strong local vibration modes (LVM) associated to N complexes. The LVM observed frequencies between 325 and 540 cm–1 are in good agreement with density functional theory supercell calculations of AlnGa4–nN complexes (n = 1,2,3,4). We find that the observed LVMs correspond to all n values including Al4N. The LVMs spectra are resonant at energies around 1.85 eV. The values of the extended phonon frequencies of the ternary compound (GaAs and AlAs-like) reveal changes in the N distribution depending on the growth conditions: A transition from random- to nonrandom nitrogen distribution is observed upon increasing the growth temperature. Our results confirm the preferential bonding of N to Al in AlGaAs:N, due to the higher Al-N bond strength as compared to the Ga-N bond.
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The effect of rapid thermal annealing on the photoluminescence of InAsN/InGaAs dot-in-a-well structures

  • Gargallo Caballero, Raquel
  • Miguel-Sanchez, J.
  • Fernández González, Alvaro de Guzmán
  • Hierro Cano, Adrián
  • Muñoz Merino, Elias
The effect of post-growth rapid thermal annealing on the optical characteristics of InAsN/InGaAs dot-in-a-well DWELL structures grown by molecular beam epitaxy on GaAs(1 0 0) has been studied. InAs/InGaAs DWELL structures have been used as a reference. Photoluminescence measurements of these samples show similar optical effects, such as a blueshift of the peak wavelength and a reduction of the full width of at half maximum PL emission, in both types of structures up to an annealing temperature of 750 °C. Nevertheless, at 850 °C, these effects are much more pronounced in the structures with N. These results suggest that an additional As–N interdiffusion process inside the InAsN quantum dots plays a dominant role in these effects at high annealing temperatures (850 °C) on InAsN/InGaAs structures.
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The Effect of the Individual Species of the N Plasma on the Characteristics of InAsN Quantum Dots Grown by MBE

  • Gargallo Caballero, Raquel
  • Fernández González, Alvaro de Guzmán
  • Miguel-Sanchez, J.
  • Hierro Cano, Adrián
  • Muñoz Merino, Elias
The influence of the different species which constitute N plasma, such as atomic nitrogen, diatomic nitrogen and ionized species, on the morphological and optical characteristics of the InAsN quantum dots (QDs) has been studied in this work. We have performed several sets of growths modifying in each one the concentration of these species. Atomic force microscopy (AFM) and photoluminescence (PL) techniques have been used to perform the surface characterization and the optical analysis of these samples, respectively. Clearly, we have found a strong correlation between the structural and optical characteristics of the InAsN QDs with the plasma composition used during the growth. Ionized species favour the high density of QDs, atomic nitrogen increase dimensions of the QDs and molecular nitrogen does not almost affect the characteristics of these nanostructures. An increment of ionized species in the plasma yields a higher density of QDs, an increase in the atomic nitrogen increases the dimensions of the QDs and the molecular nitrogen flux used does not almost affect the characteristics of these nanostructures. Also, we have found that there is not redshift of the peak wavelength of the PL emission as we increase the atomic nitrogen concentration during the growth. This may be due to equal nitrogen incorporation into the quantum dots. We supposed that the mechanism dominating in it is possible that the nitrogen incorporation in these types of nanostructures depend on another growth parameter.
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